On 2013/3/30 4:24, Alan Stern wrote:
On Fri, 29 Mar 2013, Sarah Sharp wrote:
Also, bear in mind that the proposed patch does not give userspace a
way to power off ports via usbfs. What the new code does is a
power-off reset -- it turns off power to the port, waits a short time,
and then turns
On Mon, Apr 08, 2013 at 08:58:09PM +0800, Lan Tianyu wrote:
On 2013/3/30 4:24, Alan Stern wrote:
On Fri, 29 Mar 2013, Sarah Sharp wrote:
Also, bear in mind that the proposed patch does not give userspace a
way to power off ports via usbfs. What the new code does is a
power-off reset -- it
On 2013/4/1 23:12, Alan Stern wrote:
On Mon, 1 Apr 2013, Lan Tianyu wrote:
On 2013年03月30日 01:23, Alan Stern wrote:
On Fri, 29 Mar 2013, Sarah Sharp wrote:
However, what happens if you echo 0 to pm_qos_no_power_off, the
power/control is set to auto, and there's a suspended USB device
attached
On Mon, Apr 08, 2013 at 06:29:36AM -0700, Greg KH wrote:
On Mon, Apr 08, 2013 at 08:58:09PM +0800, Lan Tianyu wrote:
On 2013/3/30 4:24, Alan Stern wrote:
On Fri, 29 Mar 2013, Sarah Sharp wrote:
Also, bear in mind that the proposed patch does not give userspace a
way to power off ports
On Mon, Apr 08, 2013 at 08:57:43AM -0700, Sarah Sharp wrote:
On Mon, Apr 08, 2013 at 06:29:36AM -0700, Greg KH wrote:
On Mon, Apr 08, 2013 at 08:58:09PM +0800, Lan Tianyu wrote:
On 2013/3/30 4:24, Alan Stern wrote:
On Fri, 29 Mar 2013, Sarah Sharp wrote:
Also, bear in mind that the
On Mon, 8 Apr 2013, Greg KH wrote:
On Mon, Apr 08, 2013 at 08:57:43AM -0700, Sarah Sharp wrote:
On Mon, Apr 08, 2013 at 06:29:36AM -0700, Greg KH wrote:
On Mon, Apr 08, 2013 at 08:58:09PM +0800, Lan Tianyu wrote:
On 2013/3/30 4:24, Alan Stern wrote:
On Fri, 29 Mar 2013, Sarah Sharp
On Mon, 8 Apr 2013, Lan Tianyu wrote:
Hi Alan:
I think current code can't achieve that power off port(whose
child device was already suspended but it was not powered off due to
NO_POWER_OFF flag setting.) via clearing NO_POWER_OFF flag. Because
at that moment, its usage count can't be
On Mon, Apr 08, 2013 at 09:01:44AM -0700, Greg KH wrote:
On Mon, Apr 08, 2013 at 08:57:43AM -0700, Sarah Sharp wrote:
On Mon, Apr 08, 2013 at 06:29:36AM -0700, Greg KH wrote:
On Mon, Apr 08, 2013 at 08:58:09PM +0800, Lan Tianyu wrote:
Hi Alan Sarah:
I just recall why I put
Cc-ing the linux-pm list and some Intel power devs, as I think this
specific discussion could benefit from a broader audience.
On Mon, Apr 08, 2013 at 12:33:00PM -0400, Alan Stern wrote:
On Mon, 8 Apr 2013, Greg KH wrote:
On Mon, Apr 08, 2013 at 08:57:43AM -0700, Sarah Sharp wrote:
On
On Monday, April 08, 2013 10:33:54 AM Sarah Sharp wrote:
On Mon, Apr 08, 2013 at 09:01:44AM -0700, Greg KH wrote:
On Mon, Apr 08, 2013 at 08:57:43AM -0700, Sarah Sharp wrote:
On Mon, Apr 08, 2013 at 06:29:36AM -0700, Greg KH wrote:
On Mon, Apr 08, 2013 at 08:58:09PM +0800, Lan Tianyu
On Mon, 8 Apr 2013, Sarah Sharp wrote:
That could work. However, we have to think about future platform power
changes as well. Coming up with a USB specific way to work around the
runtime PM core will hurt us in the long run, if we end up having to
change the runtime PM core for another
On Monday, April 08, 2013 10:55:19 AM Sarah Sharp wrote:
Cc-ing the linux-pm list and some Intel power devs, as I think this
specific discussion could benefit from a broader audience.
On Mon, Apr 08, 2013 at 12:33:00PM -0400, Alan Stern wrote:
On Mon, 8 Apr 2013, Greg KH wrote:
On
On Mon, Apr 08, 2013 at 09:39:07PM +0200, Rafael J. Wysocki wrote:
On Monday, April 08, 2013 10:55:19 AM Sarah Sharp wrote:
Cc-ing the linux-pm list and some Intel power devs, as I think this
specific discussion could benefit from a broader audience.
On Mon, Apr 08, 2013 at 12:33:00PM
On 2013年03月29日 22:11, Alan Stern wrote:
On Fri, 29 Mar 2013, Lan Tianyu wrote:
Actually, I exposed pm qos flags for usb port via dev_pm_qos_expose_flags().
It creates power/pm_qos_no_power_off under usb port sysfs directory.
User can echo 0 pm_qos_no_power_off to power off the empty port.
On 2013年03月30日 01:23, Alan Stern wrote:
On Fri, 29 Mar 2013, Sarah Sharp wrote:
However, what happens if you echo 0 to pm_qos_no_power_off, the
power/control is set to auto, and there's a suspended USB device
attached to the port with remote wakeup enabled? Will the port be
powered off? I
On Mon, 1 Apr 2013, Lan Tianyu wrote:
On 2013年03月30日 01:23, Alan Stern wrote:
On Fri, 29 Mar 2013, Sarah Sharp wrote:
However, what happens if you echo 0 to pm_qos_no_power_off, the
power/control is set to auto, and there's a suspended USB device
attached to the port with remote wakeup
On 2013/3/29 6:43, Sarah Sharp wrote:
On Thu, Mar 28, 2013 at 05:00:23PM -0400, Alan Stern wrote:
On Thu, 28 Mar 2013, Sarah Sharp wrote:
On Thu, Mar 28, 2013 at 01:11:02AM +0800, Lan Tianyu wrote:
Some devices' firmware will be broken at some points. Power down
and power on device can help
On Fri, 29 Mar 2013, Lan Tianyu wrote:
Actually, I exposed pm qos flags for usb port via dev_pm_qos_expose_flags().
It creates power/pm_qos_no_power_off under usb port sysfs directory.
User can echo 0 pm_qos_no_power_off to power off the empty port.
Before it's too late, we should consider
On Fri, Mar 29, 2013 at 02:37:24PM +0800, Lan Tianyu wrote:
On 2013/3/29 6:43, Sarah Sharp wrote:
On Thu, Mar 28, 2013 at 05:00:23PM -0400, Alan Stern wrote:
On Thu, 28 Mar 2013, Sarah Sharp wrote:
On Thu, Mar 28, 2013 at 01:11:02AM +0800, Lan Tianyu wrote:
Now I'm a bit confused and I'll
On Fri, 29 Mar 2013, Sarah Sharp wrote:
However, what happens if you echo 0 to pm_qos_no_power_off, the
power/control is set to auto, and there's a suspended USB device
attached to the port with remote wakeup enabled? Will the port be
powered off? I don't think it will with the current
On Fri, Mar 29, 2013 at 01:23:14PM -0400, Alan Stern wrote:
On Fri, 29 Mar 2013, Sarah Sharp wrote:
However, what happens if you echo 0 to pm_qos_no_power_off, the
power/control is set to auto, and there's a suspended USB device
attached to the port with remote wakeup enabled? Will the
On Fri, 29 Mar 2013, Sarah Sharp wrote:
Also, bear in mind that the proposed patch does not give userspace a
way to power off ports via usbfs. What the new code does is a
power-off reset -- it turns off power to the port, waits a short time,
and then turns power back on.
I think we
On 2013/3/28 2:45, Alan Stern wrote:
+int usb_hub_port_power_reset(struct usb_device *hdev, int port1)
+{
+ struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
+ struct usb_interface *intf = to_usb_interface(hub-intfdev);
+ int ret;
+
+ usb_autopm_get_interface(intf);
On Thu, 28 Mar 2013, Lan Tianyu wrote:
How long do you think the power should remain turned off? This code
will leave it off for only a few milliseconds at most. That may not
even be long enough for the voltage to drop all the way to 0.
The delay probably should be at least 100 ms.
On 2013/3/28 22:46, Alan Stern wrote:
On Thu, 28 Mar 2013, Lan Tianyu wrote:
How long do you think the power should remain turned off? This code
will leave it off for only a few milliseconds at most. That may not
even be long enough for the voltage to drop all the way to 0.
The delay
On Fri, 29 Mar 2013, Lan Tianyu wrote:
About the path usb: Add usb port system pm support, do you think it's
ok?
Generally yes. But why doesn't usb_port_system_suspend check for any
PM_QOS constraints? Either on the port itself or on the child device.
Alan Stern
--
To unsubscribe from this
On 2013/3/29 0:50, Alan Stern wrote:
On Fri, 29 Mar 2013, Lan Tianyu wrote:
About the path usb: Add usb port system pm support, do you think it's
ok?
Generally yes. But why doesn't usb_port_system_suspend check for any
PM_QOS constraints? Either on the port itself or on the child device.
On Fri, 29 Mar 2013, Lan Tianyu wrote:
On 2013/3/29 0:50, Alan Stern wrote:
On Fri, 29 Mar 2013, Lan Tianyu wrote:
About the path usb: Add usb port system pm support, do you think it's
ok?
Generally yes. But why doesn't usb_port_system_suspend check for any
PM_QOS constraints?
On 2013/3/29 1:49, Alan Stern wrote:
On Fri, 29 Mar 2013, Lan Tianyu wrote:
On 2013/3/29 0:50, Alan Stern wrote:
On Fri, 29 Mar 2013, Lan Tianyu wrote:
About the path usb: Add usb port system pm support, do you think it's
ok?
Generally yes. But why doesn't usb_port_system_suspend check
On Fri, 29 Mar 2013, Lan Tianyu wrote:
Ok. I just refresh patch usb: introduce usb force power off mechanism
Please have a look.
From 16f5c7c6dd00830530a9ac758af25b575e0b8731 Mon Sep 17 00:00:00 2001
From: Lan Tianyu tianyu@intel.com
Date: Tue, 26 Feb 2013 11:12:09 +0800
Subject:
On 2013/3/29 3:38, Alan Stern wrote:
On Fri, 29 Mar 2013, Lan Tianyu wrote:
Ok. I just refresh patch usb: introduce usb force power off mechanism
Please have a look.
From 16f5c7c6dd00830530a9ac758af25b575e0b8731 Mon Sep 17 00:00:00 2001
From: Lan Tianyu tianyu@intel.com
Date: Tue, 26
On Thu, Mar 28, 2013 at 01:11:02AM +0800, Lan Tianyu wrote:
Some devices' firmware will be broken at some points. Power down
and power on device can help device to rework in this case.
This patch is to add ioctl cmd USBDEVFS_POWER_RESET for usbfs node
to repower usb device. First, call
On Fri, Mar 29, 2013 at 03:51:50AM +0800, Lan Tianyu wrote:
On 2013/3/29 3:38, Alan Stern wrote:
On Fri, 29 Mar 2013, Lan Tianyu wrote:
It looks okay. When you test it, does the attached device get detected
and initialized properly?
I test usb2.0 key on my machine. It works.
Did you test
On Thu, 28 Mar 2013, Sarah Sharp wrote:
On Thu, Mar 28, 2013 at 01:11:02AM +0800, Lan Tianyu wrote:
Some devices' firmware will be broken at some points. Power down
and power on device can help device to rework in this case.
This patch is to add ioctl cmd USBDEVFS_POWER_RESET for usbfs
On Thu, Mar 28, 2013 at 05:00:23PM -0400, Alan Stern wrote:
On Thu, 28 Mar 2013, Sarah Sharp wrote:
On Thu, Mar 28, 2013 at 01:11:02AM +0800, Lan Tianyu wrote:
Some devices' firmware will be broken at some points. Power down
and power on device can help device to rework in this case.
Some devices' firmware will be broken at some points. Power down
and power on device can help device to rework in this case.
This patch is to add ioctl cmd USBDEVFS_POWER_RESET for usbfs node
to repower usb device. First, call hub_port_logical_disconnect() to
disconnect device. Second, Power down
Regards
Tianyu Lan
-Original Message-
From: Lan, Tianyu
Sent: Thursday, March 28, 2013 1:11 AM
To: gre...@linuxfoundation.org; sarah.a.sh...@linux.intel.com;
st...@rowland.harvard.edu
Cc: linux-usb@vger.kernel.org; Lan, Tianyu
Subject: [PATCH 2/4] usb: introduce usb force power off mechanism
On Thu, 28 Mar 2013, Lan Tianyu wrote:
Some devices' firmware will be broken at some points. Power down
and power on device can help device to rework in this case.
This patch is to add ioctl cmd USBDEVFS_POWER_RESET for usbfs node
to repower usb device. First, call
On Wed, 27 Mar 2013, Lan, Tianyu wrote:
A small tool to test this patch.
#include stdio.h
#include unistd.h
#include fcntl.h
#include errno.h
#include sys/ioctl.h
#include linux/usbdevice_fs.h
#define USBDEVFS_POWER_RESET _IO('U', 28)
int main(int argc, char **argv)
{
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